A six-point locking device for repeated locking of test quality

Abstract

A six-point locking device for repeated locking of a test mass, the present invention relates to a locking device, in order to solve the problems of inaccurate locking position and uneven locking force of the existing test mass locking mechanism, the present invention symmetrically provides a six-point locking device on the upper and lower sides of the test mass, each six-point locking device includes an upper shell, an ultrasonic motor, a gear reducer, a screw nut assembly and a push rod assembly, the ultrasonic motor, the gear reducer and the screw nut assembly are all located in the upper shell, the output shaft of the ultrasonic motor is connected to the screw nut assembly through the gear reducer, and the screw nut assembly is connected to the push rod assembly. The locking device designed by the present invention is small, lightweight, high-precision, reliable in clamping, and ensures that the test mass is completely locked and positioned before release. The present invention belongs to the field of aerospace technology.

Description

Technical Field

[0001] The invention relates to a locking device, in particular to a six-point locking device for repeated locking of test quality, and belongs to the field of aerospace technology. Background Art

[0002] Gravitational waves are matter waves that transmit energy in the form of gravitational radiation. Their introduction has proposed a new means for detecting nature. However, due to the very small amplitude of gravitational waves, they are difficult to measure and detect. In the 1990s, the European Space Agency and NASA jointly proposed the space laser interferometer gravitational wave detection project - the LISA program. The space gravitational wave detection light source emits lasers, which are reflected by the surface of the test mass (TM) and are received by the receiver. When the gravitational waves pass through the optical path, they cause changes in the light. The changes are received by the receiver and the existence of gravitational waves can be detected. However, gravitational waves have a low frequency and small amplitude, which places strict requirements on the accuracy of the detection system. Therefore, for the testing quality of core components, it is required to be locked, released and captured accurately and without disturbance.

[0003] The existing test mass locking mechanisms in China mainly use a four-rod locking scheme, see: "Design and Analysis of Low-Disturbance Test Mass Locking and Release Mechanism", Fang Jianyong, Master's thesis of Wanfang. The eight-point locking scheme adopted in this thesis over-positions the test mass surface with four push rods on one side, which can easily cause uneven locking force loaded on the test mass surface due to inconsistent elongation of each push rod, resulting in damage to the test mass surface. Summary of the invention

[0004] The present invention aims to solve the problem that the existing measurement mass locking mechanism adopts a four-rod locking scheme and the four-rod locking scheme on one side over-positions the test mass surface, and further proposes a six-point locking device for repeated locking of the test mass.

[0005] The technical solution adopted by the present invention to solve the above problems is:

[0006] The present invention has a six-point locking device symmetrically arranged on the upper and lower sides of the test mass, each of the six-point locking devices includes an upper shell, an ultrasonic motor, a gear reducer, a screw nut assembly and a push rod assembly, the ultrasonic motor, the gear reducer and the screw nut assembly are all located in the upper shell, the output shaft of the ultrasonic motor is connected to the screw nut assembly through the gear reducer, and the screw nut assembly is connected to the push rod assembly.

[0007] Furthermore, the upper shell has a "D"-shaped structure, and an opening for installing the ultrasonic motor is provided on a vertical side. Three rectangular holes are evenly distributed along the circumferential direction on the side wall of the upper shell, and a threaded hole is provided at the bottom of each rectangular hole, and the upper shell is fixed to the outer shell by screws.

[0008] Furthermore, the upper surface of the upper shell is provided with a "D"-shaped limiting hole that cooperates with the screw nut assembly.

[0009] Furthermore, the screw nut assembly includes a nut, two bearings and a screw, the screw includes a D-shaped section, a cylindrical section and a circular body, one end of the D-shaped section is inserted into the D-shaped limiting hole of the upper shell, and the other end is connected to the cylindrical section, the circular body is sleeved on the lower part of the cylindrical section, the nut is threadedly connected to the cylindrical section and is located at the upper part of the circular body, two bearings are sleeved on the cylindrical section and are respectively located at the upper and lower parts of the nut, and the lower end of the cylindrical section is connected to the push rod assembly.

[0010] Furthermore, the D-shaped segment, the cylindrical segment and the round cake body are integrally formed.

[0011] Furthermore, the output shaft of the ultrasonic motor is fixedly connected to the first gear of the gear reducer, the second gear is meshed with the first gear, and the nut of the screw nut assembly is fixedly connected to the second gear.

[0012] Furthermore, the push rod assembly includes three push rods, a disc body, an outer shell, an upper disc spring, a lower disc spring, a sensor, a brake pad and a cylinder body. The three push rods are evenly distributed along the circumferential direction of the disc body, one end of each push rod is connected to the lower surface of the disc body, the upper surface of the disc body is installed with a cylinder body, and the cylinder body is sequentially provided with an upper disc spring, a lower disc spring, a sensor and a brake pad from top to bottom. The lower end of the cylindrical section passes through the cylinder body, the upper disc spring, the lower disc spring, the sensor and the brake pad in sequence and is fixed to the disc body. The upper disc spring is located at the upper part of the circular body of the screw rod, and the lower disc spring is located at the lower part of the circular body. The three push rods, the disc body and the cylinder body are all located in the outer shell.

[0013] Furthermore, the brake pad is a disc body, a threaded hole for connecting the cylindrical section of the screw rod is provided in the middle of the upper surface of the brake pad, four small cylinders are evenly distributed along the circumferential direction on the upper surface of the brake pad, and a strain gauge is provided between every two adjacent small cylinders.

[0014] Furthermore, a hemispherical protrusion is provided at the bottom of each push rod.

[0015] Furthermore, the three push rods are arranged in an equilateral triangle.

[0016] The beneficial effects of the present invention are:

[0017] 1. The present invention is driven by an ultrasonic motor and has no magnetized structure, so it will not cause magnetic field interference to the detection system and has high safety and reliability.

[0018] 2. The locking structure designed by the present invention is small, lightweight, high-precision and reliable in clamping.

[0019] 3. The present invention simplifies the complexity of the design through the equilateral triangle design of the three ejector pins, avoids over-positioning, reduces the number of sensors, and improves processing accuracy.

[0020] 4. The present invention improves transmission accuracy through screw nut transmission, reduces the weight of the transmission part, and achieves lightweight design.

[0021] 5. The end of each push rod in the present invention is hemispherical, corresponding to the ball socket of the test mass, which is convenient for positioning and applying force.

[0022] 6. The present invention can avoid the situation where the force is difficult to accurately control during the loading process through the design of the upper and lower disc springs and brake pads. When the force is loaded into the target force range, the force loading can be stopped at this time, and the state of the disc spring assembly can be controlled by adjusting the position of the brake pad, thereby achieving precise force control. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a schematic diagram of the overall structure of the present invention;

[0024] Figure 2 It is a structural schematic diagram of the upper shell of the present invention;

[0025] Figure 3 It is a structural schematic diagram of the screw rod of the present invention;

[0026] Figure 4 It is a structural schematic diagram of the ejector assembly of the present invention;

[0027] Figure 5 It is a structural schematic diagram of the brake pad of the present invention. DETAILED DESCRIPTION

[0028] The six-point locking device for repeated locking of the test mass described in this embodiment is assembled on the ground before launching, mainly to ensure that the test mass is completely locked and positioned before release. When entering the working state, the locking mechanism cooperates with the subsequent release and capture mechanism to complete the low-disturbance release.

[0029] like Figure 1As shown, a six-point locking device is symmetrically provided on the upper and lower sides of the test mass 15, and each six-point locking device includes an upper shell 1, an ultrasonic motor 2, a gear reducer 3, a screw nut assembly and a push rod assembly. The ultrasonic motor 2, the gear reducer 3 and the screw nut assembly are all located in the upper shell 1. The output shaft of the ultrasonic motor 2 is connected to the screw nut assembly through the gear reducer 3, and the screw nut assembly is connected to the push rod assembly. The screw nut assembly includes a nut 4, two bearings 5 ​​and a screw 6, and the screw 6 includes a D-shaped segment 6-1, a cylindrical segment 6-2 and a round cake body 6-3; the push rod assembly includes three push rods 7, a disc body 8, a shell 9, an upper disc spring 10, a lower disc spring 11, a sensor 12, a brake pad 13 and a cylinder 14;

[0030] The power of the locking mechanism is provided by the ultrasonic motor 2, and the power is transmitted by the screw-nut assembly in conjunction with the gear reducer 3 to the three push rods 7 of the push rod assembly to lock the test mass 15. The hemispherical structure at the lower end of each push rod 7 contacts and clamps the ball socket surface of the test mass 15 to complete the positioning.

[0031] Preferably, the ultrasonic motor 2 can be replaced by a common servo motor if there is no requirement for a non-magnetized design.

[0032] like Figure 2 As shown, the upper shell 1 is approximately D-shaped, one side is processed into a plane, and rectangular holes 1-2 are processed at 90° and 180° adjacent to the side, and threaded holes are processed at the bottom of the rectangular holes, so that the upper shell 1 and the outer shell 9 can be installed by screws; the ultrasonic motor 2 is installed on the plane opening side of the upper shell 1 and is powered by it, and the output shaft and the gear reducer 3 are interference fit to transmit power to the screw nut assembly, driving the nut 4 to rotate;

[0033] like Figure 1 and Figure 3 As shown, the screw nut assembly includes a nut 4, two bearings 5 ​​and a screw 6, wherein the screw 6 includes a D-shaped section 6-1, a cylindrical section 6-2 and a circular body 6-3, one end of the D-shaped section 6-1 is inserted into the D-shaped limiting hole 1-3 of the upper shell 1, and the other end is connected to the cylindrical section 6-2, the circular body 6-3 is sleeved on the lower part of the cylindrical section 6-2, the nut 4 is threadedly connected to the cylindrical section 6-2 and is located on the upper part of the circular body 6-3, the two bearings 5 ​​are sleeved on the cylindrical section 6-2, and are respectively located on the upper and lower parts of the nut 4, and the lower end of the cylindrical section 6-2 is connected to the push rod assembly. The top end of the screw 6 is processed into a D-shaped structure, which cooperates with the D-shaped groove of the upper shell 1 to ensure that the screw 6 can only move up and down and cannot rotate;

[0034] like Figure 4As shown, the middle part of the screw rod 6 is processed into a round cake shape, which cooperates with the push rod assembly to transmit the force to the three push rods 7 for locking; the upper part of the push rod assembly is a cylindrical body 14, the middle part is a disc body 8, and the three push rods 7 are symmetrically arranged below the disc body 8; the upper cylindrical part cooperates with the bottom of the screw rod 6, and an upper disc spring 10, a lower disc spring 11, a sensor 12 and a brake pad 13 are installed inside, and the force is indirectly transmitted to the three push rods 7 by the disc spring; the lower disc spring 11 is in contact with the sensor 12, and a brake pad 13 is provided below the sensor 12.

[0035] Preferably, the upper disc spring 10 and the lower disc spring 11 can be replaced by springs.

[0036] Preferably, the bottoms of the three push rods 7 are processed into spherical structures, which are in contact with the spherical surface on the test mass 15 for positioning. When the force transmitted by the upper disc spring 10 and the lower disc spring 11 is applied to the sensor 12, the deformation is caused and the information is received by the strain gauge 13-3 to measure the corresponding locking force.

[0037] like Figure 5 As shown, the brake pad 13 is a disc body, and a threaded hole 13-1 for connecting the cylindrical section 6-2 of the screw rod is provided in the middle of the upper surface of the brake pad 13, and four small cylinders 13-2 are evenly distributed on the upper surface of the brake pad 13 along the circumferential direction, and a strain gauge 13-3 is provided between each two adjacent small cylinders 13-2 to receive the force signal from the disc spring; the brake pad 13 and the lower end part of the screw rod 6 are matched through threads, and the locking force applied can be fine-tuned by adjusting the brake pad 13.

[0038] Working principle:

[0039] 1. Install each component:

[0040] First, the ultrasonic motor 2 is installed on the plane side of the upper shell 1 and powered by it. The output shaft of the ultrasonic motor 2 transmits power to the screw nut 4 through interference fit with the gear reducer 3; the upper and lower ends of the screw nut 4 are interference fit with two bearings installed on the upper shell 1 and the outer shell 9 for rotation; the top of the screw 6 is processed into a D-shaped structure, which cooperates with the D-shaped limiting holes 1-3 of the upper shell 1 to ensure that the screw 6 can only move up and down; the middle part of the screw 6 is processed into a round cake shape, which cooperates with the three push rods 7 to transmit force to the three push rods 7 for locking; the three push rods 7 are The upper part is cylindrical, the middle part is round, and the lower part is three push rods 7 symmetrically arranged below the disc body 8; the upper cylinder 14 cooperates with the bottom of the screw 6, and the upper and lower disc springs 10 and 11 are installed inside, and the force is indirectly transmitted to the three push rods 7 by the disc springs; the lower disc spring 11 contacts the sensor assembly 12, and the brake pad 13 is located at the lower part of the sensor 12. The brake pad 13 and the lower end of the screw 6 are threaded, and the applied locking force can be fine-tuned by adjusting the brake pad 13; the lower ends of the three push rods 7 are processed into spherical surfaces, which contact the ball socket surface on the test mass 15 for positioning. When the force transmitted from the upper disc spring 10 and the lower disc spring 11 is applied to the sensor 12, the deformation is caused, and the strain gauge receives information and measures the corresponding locking force.

[0041] 2. Working process:

[0042] Due to the large vibration during the launch process, the ejector rod 7 is required to provide a large locking force to lock the test mass without damaging the surface of the test mass. The accuracy of the work during the ground installation phase is particularly important. The specific working process is as follows:

[0043] During the ground installation and locking stage, the staff first assembles the mechanism on the ground. The ultrasonic motor 2 rotates forward to provide power, and after being transmitted by the gear reducer 3, the power is transmitted to the screw nut 4. At this time, the D-type limit hole 1-3 of the shell limits the rotation of the screw 6, and the screw nut 4 cooperates with the bearing 5 to rotate, thereby driving the screw 6 to move in the direction of the test mass 15. The lower end of the screw 6 is assembled with the upper disc spring 10, the lower disc spring 11, the force sensor 12, the brake pad 13, and the three push rod structures 7, which move together and transmit force through the upper disc spring 10 and the lower disc spring 11. The force sensor 12 is located between the lower disc spring 11 and the brake pad 13. When the force on the force sensor 12 reaches the target value, the ultrasonic motor 2 stops working and then stops power loading. By adjusting the position of the brake pad 13, the state of the upper disc spring 10 and the lower disc spring 11 can be adjusted, thereby controlling the locking force applied by the locking mechanism to achieve precise force control.

[0044] During the track unlocking stage, the ultrasonic motor 2 slowly reverses and transmits power to the screw nut assembly. At this time, the D-type limit hole 1-3 of the upper shell 1 limits the rotation of the screw 6, and the screw nut 4 cooperates with the bearing 5 to rotate, thereby driving the screw 6 to move away from the test mass. The lower end of the screw 6 is assembled with the upper disc spring 10 and the lower disc spring 11, the force sensor 12, the brake pad 13, and the three push rods 7, which move together and transmit force through the upper disc spring 10 and the lower disc spring 11. The force sensor assembly 12 is located between the lower disc spring 11 and the brake pad 13. When the measured force on the force sensor 12 is close to 0, the ultrasonic motor 2 accelerates the reversal speed so that the push rod 7 can quickly retreat to the predetermined position to avoid unnecessary disturbance to the test mass 15.

[0045] Repeat the above steps to complete the repeated locking and unlocking of the test quality.

[0046] The above is only a preferred embodiment of the present invention and does not limit the present invention in any form. Although the present invention has been disclosed as a preferred embodiment as above, it is not used to limit the present invention. Any technician familiar with this profession can make some changes or modify the technical contents disclosed above into equivalent embodiments without departing from the scope of the technical solution of the present invention. However, any simple modification, equivalent replacement and improvement made to the above embodiments without departing from the content of the technical solution of the present invention, based on the technical essence of the present invention, within the spirit and principles of the present invention, still fall within the protection scope of the technical solution of the present invention.

Claims

1. A six-point locking device for repeated locking of test quality, characterized in that: A six-point locking device is symmetrically arranged on the upper and lower sides of the test mass (15), each of the six-point locking devices comprising an upper shell (1), an ultrasonic motor (2), a gear reducer (3), a screw nut assembly and a push rod assembly, the ultrasonic motor (2), the gear reducer (3) and the screw nut assembly are all located in the upper shell (1), the output shaft of the ultrasonic motor (2) is connected to the screw nut assembly via the gear reducer (3), and the screw nut assembly is connected to the push rod assembly; The push rod assembly comprises three push rods (7), a disk body (8), a housing (9), an upper disc spring (10), a lower disc spring (11), a sensor (12), a brake pad (13) and a cylinder body (14). The three push rods (7) are evenly distributed along the circumference of the disk body (8) to form an equilateral triangle. One end of each push rod (7) is connected to the lower surface of the disk body (8). The upper surface of the disk body (8) is provided with a cylinder body (14). The cylinder body (14) is provided with a plurality of push rods (7) and a plurality of push rods (7) arranged in sequence from top to bottom. An upper disc spring (10), a lower disc spring (11), a sensor (12) and a brake pad (13) are provided. The lower end of the cylindrical section (6-2) of the screw rod (6) of the screw rod nut assembly passes through the cylindrical body (14), the upper disc spring (10), the lower disc spring (11), the sensor (12) and the brake pad (13) in sequence and is then fixed to the disc body (8). The upper disc spring (10) is located at the upper part of the disc body (6-3) of the screw rod (6), and the lower disc spring (11) is located at the lower part of the disc body (6-3).

2. A six-point locking device for repeated locking of test mass according to claim 1, characterized in that: The brake pad (13) is a disc body, a threaded hole (13-1) for connecting the screw rod cylindrical section (6-2) is provided in the middle of the upper surface of the brake pad (13), four small cylinders (13-2) are evenly distributed on the upper surface of the brake pad (13) along the circumferential direction, and a strain gauge (13-3) is provided between every two adjacent small cylinders (13-2).

3. A six-point locking device for repeated locking of test mass according to claim 1, characterized in that: A hemispherical protrusion (7-1) is provided at the bottom of each push rod (7).

4. A six-point locking device for repeated locking of test mass according to claim 1, characterized in that: The upper shell (1) is in a "D"-shaped structure, and an opening (1-1) for installing an ultrasonic motor (2) is provided on one vertical side. Three rectangular holes (1-2) are evenly distributed along the circumferential direction on the side wall of the upper shell (1), and a threaded hole is provided at the bottom of each rectangular hole (1-2).

5. A six-point locking device for repeated locking of test mass according to claim 4, characterized in that: The upper surface of the upper shell (1) is provided with a "D"-shaped limiting hole (1-3) that cooperates with the screw nut assembly.

6. A six-point locking device for repeated locking of test mass according to claim 5, characterized in that: The screw nut assembly comprises a nut (4), two bearings (5) and a screw (6); the screw (6) comprises a D-shaped section (6-1), a cylindrical section (6-2) and a circular body (6-3); one end of the D-shaped section (6-1) is inserted into a D-shaped limiting hole (1-3) of the upper shell (1), and the other end is connected to the cylindrical section (6-2); the circular body (6-3) is sleeved on the lower part of the cylindrical section (6-2); the nut (4) is threadedly connected to the cylindrical section (6-2) and is located on the upper part of the circular body (6-3); the two bearings (5) are sleeved on the cylindrical section (6-2) and are respectively located on the upper part and the lower part of the nut (4); and the lower end of the cylindrical section (6-2) is connected to the push rod assembly.

7. A six-point locking device for repeated locking of test mass according to claim 6, characterized in that: The D-shaped segment (6-1), the cylindrical segment (6-2) and the round cake body (6-3) are integrally formed.

8. A six-point locking device for repeated locking of test mass according to claim 1, characterized in that: The output shaft of the ultrasonic motor (2) is fixedly connected to the first gear of the gear reducer (3), the second gear is meshed with the first gear, and the nut (4) of the screw nut assembly is fixedly connected to the second gear.

Images